<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.main {
				height: 800px;
				display: grid;
				grid-template-columns: 3fr 7fr;
				grid-template-rows: 100%;
			}
			.left {
				background-color: red;
			}
			.right {
				background-color: blue;
			}
		</style>
	</head>
	<body>
		<div class="main">
			<div class="left"></div>
			<div class="right"></div>
		</div>
	</body>
</html>
